Amalgamation of ores.



CALEB Gr. COLLINS, OF VVOODMERE, YORK, ASSIGNOR TO CALVIN AMORY STEVENS, OF NEW YORK, N. Y.

AMALGAMATION OF ORES.

SPECIFICATION formingpart of Letters Patent No. 668,283, dated. February 19, 1901.

Application filed January 13, 1900.

To all whom it may concern:

Be it known that I, CALEB G. GoLLINs, a citizen of the United States, residing at Woodmere, in the county of Queens and State of New York have invented certain new and useful Improvements in the Amalgamation of Ores, of which the following is a specification sufficient to enable others skilled in the art to which the invention appertains to make and use the same.

My invention is designed to effect a more rapid and thorough extraction of metal from the ore or gangue than has heretofore been practicable.

My invention consists, primarily, in producing a sodium amalgam by electrolysis and simultaneously introducing into and agitating therewith an ore containing a metal an amalgam of which is desired, said sodium amalgam being in direct communication with the sodium electrolyte, and, secondarily, in employing a U-shaped body of sodium amalgam electrolytically producing or regenerating the amalgam of sodium on the surface at one extremity, introducing into the body of sodium amalgam below the surface of the second extremity an ore containing the metal of an amalgam of which is desired, and allowing said ore to ascend by gravity to the surface of said second extremity and removing the depleted ore or gangue from above the surface of the second extremity.

The accompanying drawing represents a vertical section of apparatus designed to give practical eifeot to my invention.

The amalgamating-tank A is preferably, although not necessarily, of cylindrical form, arranged vertically and formed of a metal not affected by mercury. V

B is a stand-pipe which extends from near the bottom of the cylinder A to a height sufficient to render gravity available in forcing the ore-pulp introduced through said pipe B into and through the column of mercury in the cylinder A, the level of which mercury is indicated by the line m m. The pipe B is supported so as to be free to rotate upon its longitudinal axis by any suitable mechanical expedient, as by shoulders I) b, resting upon the upper ends of the bearings O C. It is provided with a power-pulley W, by which it Serial No. 1,274. (No specimens.)

is rotated, and with a funnel-shaped mouth Q at its upper extremity to facilitate the introduction of the ore or pulp.

D D represent a series of iron plates or disks secured rigidly to the pipe B and rotating therewith. These plates D are perforated; but the plates are so arranged with relation to each other that the perforations in adjoining plates do not coincide. The series of plates D D are designed to be immersed in the mercury. The upper plate D, in addition to being perforated, is provided with a series of iron rods (1, extending downward from its under surface to within, say, about an inch of the surface at m of the mercury.

Extending from the side of the cylinder, near its lower extremity, is a pipe E, projecting upward above the line of mercury in the cylinder A and provided at top with a vessel F for the reception of a solution of sodium salt. P is a carbon plate situated in said soda-tank F and representing the positive pole or anode of an electrical circuit of which 19 is a symbolical representation of the conductor from a source of electricity.

N is the cathode or negative pole,connected by the conductor n with a source of electricity. This cathode consists of a comparatively large plate of carbon supported upon suitable insulators at the bottom of the cylinder A, below the stand-pipe B.

H is an outlet or overflow pipe for the escape of pulp, &c.

The operation is as follows: The ore reduced to the desired degree of fineness is introduced into the hopper or funnel Q, and a fluid vehicle used to facilitate its passage to the body of mercury below. Water or even air pressure may be used as such a vehicle. The tank E is supplied with a solution of sodium salt, such as sodium chlorid, (common salt,) which descends through the pipe E into the level of the mercuryin the tank A. The electricity being turned on, sodium is formed in the immediate presence of the mercury and is immediately taken up or absorbed thereby. It is obvious that the natural tendency of the pulp, owing to the height of the stand-pipe E, will be to force itself into the body of mercury above the cathode N, after which the greater specific gravity of the mercury will tend to force the pulp gangue up.-

ward into the space above the mercury to es? cape through the overflow-pipe H. This action is retarded by the plates D, which cause the pulp to deviate constantly from a straight line of passage by reason of the fact that the perforations in the adjoining plates do not coincide. This action is further augmented and a thorough admixture of the pulp and mercury assured by the rotation of the plates D with the tube B. By this means it is rendered practically impossible for any of the metal to escape without exposure to and contact with the mercury, and as the latteris kept bright and active by the presence of the newlyformed sodium the percentage of amalgam attained is largely increased. v Asthe pulprises above the level m m of the mercury it is thoroughly stirred and agitated by the rods 01 on the disk D, thereby disengaging any mercury that may have risen with the pulp and allowing it to fall back into the body of mercury bebelow. The exhausted pulp escapes through pipe H. It can readily be seen that as the pulp or comminuted ore is fed into the mercury containing sodium amalgam near the bottom of the second extremity of the U-shaped body it is brought in close or immediate contact with the mercury owing to the increased hydrostatic pressure at that point, and therefore any particles of metal will be immediately absorbed or dissolved, leaving the exhausted pulp to ascend and accumulate upon the surface, to be withdrawn from time to time as desired. It is well known that mercury will take up or absorb sodium and that Water will decompose and separate it from the mercury. Thus the sodium formed on the cathode in the bottom of the cylinder A will rise with the mercury until decomposed by water, the presence of the sodium keeping the mercury clean and active and in the best condition possible for forming an amalgam of the ore contained in the pulp. The formation of fresh sodium at the cathode and its continuous decomposition by the water present is the important practical advantage attained, since if the sodium remained in the mercury it would cause the mercury to grow hard and crusty, and thereby destroy its receptiveness for the metal. Thus it will be seen that it is the actual generation or formation of the sodiumdirectly Within the mercury during the introduction of the ore containing the metal desired, without interposition of porous diaphragm or other medium of electrical resistance, that is the important and distinguishing feature of my invention, the sodium in its nascent state being much more active and effective in preventing the fouling or flowering of the mercury than when introduced in any other manner. The constant removal of the sodium by solution before it deteriorates in efficiency and the continuous formation of fresh active sodium at the cathode keep the mercury-bath constant and uniform in characterand effectiveness, This, together with the enforced and positive admixture of the pulp with the mercury, insures the elimination from the pulp and the combination with the mercury of practically all the metal in the pulp, if the latter hasbeen reduced to a sufficient degree of fineness. This result is largely contributed to by the perforated disks D, which thoroughly break up the mess of ore in the pulp by causing it to pass through the numerous holes in the plates, deviating in its course in doing so. The motion of the plates also retards the upward flow of the pulp and has a scouring effect on the ore therein, making it more receptive to the mercury.

It is to be understood that while I have herein described the use of anode and cathode of carbon other suitable substances may be used for the electric terminals.

I am aware that sodium salts have been electrolyzed employing mercury as a cathode, the solution of sodium salt being in direct communication with the mercury and the sodium liberated being absorbed, thereby producing sodium amalgam. I am also aware that pulverized ores have been floated upon mercury containing sodium amalgam for the purpose of amalgamating the metal contained in such ores. It can be seen, however, that in this case the amalgamating action is purely superficial, the metal therein contained not coming in close contact with the mercury under pressure as accomplished in my process. In my process a U-shaped body of mercury is employed, and the process of producing the alkali-metal amalgam and amalgamating the metal from the com minuted ore is carried out continuously without interruption, a U: shaped body of mercury consisting of two perpendicular columns serving as a means of producing at one extremity the alkali-metal amalgam and diffusing the same throughout the body of mercury by hydrostaticpressure, while at the same time it allows the comminuted ore to be fed into the mercury containing the alkal-imetal amalgam at or near the bottom of the second column of mercury, so that the metal in the comminuted ore is brought intoimmediate contact with the mercury under hydrostatic pressure, the gangue or residue being removed'by upward displacement without bringing the same into contact with the solution of alkali electrolyte or contaminating or. retarding the electrolytic process in any manner whatsoever. The body of the mercury from one column to the other being free and unobstructed afiords a means of conveying the alkali-metal amalgam continuously from its point of production to the point of utilization, a means for bringing the mercury in contact with the ore containing the metal to be amalgamated under hydrostatic pressure, and a means of continuously feeding the ore thereto and withdrawing the gangue or residue therefrom without intermercury, whereby a continuous supply of sodium amalgam is maintained without possible commingling of the pulp and electrolytic solution and the diffusion of said sodium amalgam through the mercury is promoted by the agitation due to the submergence and agitation of the ore, substantially as described.

CALEB G. COLLINS. Witnesses:

GEO. WM. MIATT, D. W. GARDNER. 

